Automatic generation of optimized flyable path is a key technology and challenge for autonomous unmanned aerial vehicle (UAV) formation system. Aiming to improve the rapidity and optimality of automatic path planner, this paper presents a three dimensional path planning algorithm for UAV formation based on comprehensively improved particle swarm optimization (PSO). In the proposed method, a chaos-based Logistic map is firstly adopted to improve the particle initial distribution. Then, the common used constant acceleration coefficients and maximum velocity are designed to adaptive linear-varying ones, which adjusts to the optimization process and meanwhile improves solution optimality. Besides, a mutation strategy that undesired particles are replaced by those desired ones is also proposed and the algorithm convergence speed is accelerated. Theoretically, the comprehensively improved PSO not only speeds up the convergence but also improves the solution optimality. Finally, Monte-Carlo simulation for UAV formation under terrain and threat constraints are carried out and the results illustrate the rapidity and optimality of the proposed method.

Efficient path planning for UAV formation via comprehensively improved particle swarm optimization

A multi-objective pigeon-inspired optimization approach to UAV distributed flocking among obstacles

The recent emergence of Internet-of-Things (IoT) technologies in mission-critical applications in the maritime industry has led to the introduction of the Internet-of-Ships (IoS) paradigm. IoS is a novel application domain of IoT that refers to the network of smart interconnected maritime objects, which can be any physical device or infrastructure associated with a ship, a port, or the transportation itself, with the goal of significantly boosting the shipping industry toward improved safety, efficiency, and environmental sustainability. In this article, we provide a comprehensive survey of the IoS paradigm, its architecture, its key elements, and its main characteristics. Furthermore, we review the state of the art for its emerging applications, including safety enhancements, route planning and optimization, collaborative decision making, automatic fault detection and preemptive maintenance, cargo tracking, environmental monitoring, energy-efficient operations, and automatic berthing. Finally, the presented open challenges and future opportunities for research in the areas of satellite communications, security, privacy, maritime data collection, data management, and analytics, provide a road map toward optimized maritime operations and autonomous shipping.

Internet of Ships: A Survey on Architectures, Emerging Applications, and Challenges

This paper addresses the co-design problem of a fault detection filter and controller for a networked-based unmanned surface vehicle (USV) system subject to communication delays, external disturbance, faults, and aperiodic denial-of-service (DoS) jamming attacks. First, an event-triggering communication scheme is proposed to enhance the efficiency of network resource utilization while counteracting the impact of aperiodic DoS attacks on the USV control system performance. Second, an event-based switched USV control system is presented to account for the simultaneous presence of communication delays, disturbance, faults, and DoS jamming attacks. Third, by using the piecewise Lyapunov functional (PLF) approach, criteria for exponential stability analysis and co-design of a desired observer-based fault detection filter and an event-triggered controller are derived and expressed in terms of linear matrix inequalities (LMIs). Finally, the simulation results verify the effectiveness of the proposed co-design method. The results show that this method not only ensures the safe and stable operation of the USV but also reduces the amount of data transmissions.

Fault Detection Filter and Controller Co-Design for Unmanned Surface Vehicles Under DoS Attacks

This paper aims to solve the path following problem for an underactuated unmanned-surface-vessel (USV) based on deep reinforcement learning (DRL). A smoothly-convergent DRL (SCDRL) method is proposed based on the deep Q network (DQN) and reinforcement learning. In this new method, an improved DQN structure was developed as a decision-making network to reduce the complexity of the control law for the path following of a three-degree of freedom USV model. An exploring function was proposed based on the adaptive gradient descent to extract the training knowledge for the DQN from the empirical data. In addition, a new reward function was designed to evaluate the output decisions of the DQN, and hence, to reinforce the decision-making network in controlling the USV path following. Numerical simulations were conducted to evaluate the performance of the proposed method. The analysis results demonstrate that the proposed SCDRL converges more smoothly than the traditional deep Q learning while the path following error of the SCDRL is comparable to existing methods. Thanks to good usability and generality of the proposed method for USV path following, it can be applied to practical applications.

Path Following Optimization for an Underactuated USV Using Smoothly-Convergent Deep Reinforcement Learning

This paper investigates the path planning problem for unmanned surface vehicle (USV), wherein the goal is to find the shortest, smoothest, most economical and safest path in the presence of obstacles and currents, which is subject to the collision avoidance, motion boundaries and velocity constraints. We formulate this problem as a multi-objective nonlinear optimization problem with generous constraints. Then, we propose the dynamic augmented multi-objective particle swarm optimization algorithm to achieve the solution. With our approach, USV can select the ideal path from the Pareto optimal paths set. Numerical simulations verify the effectiveness of our formulated model and proposed algorithm.

Multi-objective path planning for unmanned surface vehicle with currents effects.

The invention discloses a self-adaptive adjustable device arranged on a maritime cruising search and rescue unmanned ship. The self-adaptive adjustable device comprises an environment information collecting module, a data processing communication module and an adjustable buoyancy tank executing module; the adjustable buoyancy tank executing module comprises adjustable buoyancy tanks symmetrically arranged on the two sides of the ship and telescopic slide rails, and the telescopic slide rails are used for being stretched out and drawn back towards the outer sides or the inner sides of the ship; each telescopic slide rail is provided with a driving device body, an output shaft of each driving device body is connected with one end of a corresponding rotary bracket, and the other end of each rotary bracket is connected with the corresponding adjustable buoyancy tank; and the driving device bodies are used for controlling the draft of the adjustable buoyancy tanks. When an unmanned plane takes off or lands on the unmanned ship, the adjustable buoyancy tanks are spread, the initial stability of the unmanned ship is improved, overturn is avoided, and the stable performance of the unmanned ship is improved; and when the unmanned ship needs to conduct cruising search and rescue or carry the unmanned plane and return, the adjustable buoyancy tanks can be drawn back, and the sailing performance of the unmanned ship is fully achieved.

Self-adaptive adjustable device arranged on maritime cruising search and rescue unmanned ship

Wind energy plays a significant role in the energy consumption reduction of the sail-assisted vessels. During the navigation process, how to select the ideal airfoil sails is crucial for the vessel...

https://journals.sagepub.com/doi/pdf/10.1177/1687814018771254

New insights into airfoil sail selection for sail-assisted vessel with computational fluid dynamics simulation:

The invention discloses a self-adapting sail capable of generating power The self-adapting sail comprises a movable wing-type blade, a hydraulic drive device, a hydraulic positioning device, a mast and a power generator, wherein the mast is arranged on a ship through a bearing; the lower end of the mast is connected to the input shaft of the power generator through a transmission mechanism; the movable wing-type blade consists of a plurality of blades; the movable wing-type blade is arranged in a slide block slot in the upper end of the mast through a supporting slide block mechanism; while closed, the outer surface of the movable wing-type blade is smoothly transited to integrally form a circular-arc-shaped sail form; and when power generation is needed, the movable wing-type blade is driven by the hydraulic drive device to stretch, and the position of each blade is fixed through the hydraulic positioning device, so that a vertical-axis wind driven generator form is integrally formed According to the self-adapting sail, the ship utilizes the sail to assist navigation during navigation, and utilizes a fan to assist power generation during mooring, so that the utilization rate of wind energy is remarkably increased, and energy resources are saved

Self-adapting sail capable of generating power

The utility model discloses an unmanned surveying vessel for underwater topography survey and drawing, including the hull, be equipped with environmental information collection system, data processing device, measuring platform on the hull, measuring platform sets firmly on the hull through clamping mechanism, is equipped with the bracing piece in measuring platform department, is equipped with the receiver in the upper end of bracing piece, is equipped with the transducer at the lower extreme of bracing piece, the receiver is used for the elevation location, the transducer is used for carrying on the degree of depth and measures, the receiver links to each other with the transducer, the receiver is connected with transducer and the fathometer that sets up on the hull. The utility model discloses a carry on the measuring platform of the dismouting of being convenient for on the hull, can repack general boat into unmanned surveying vessel, carry out unmanned survey and drawing, can go on other simultaneously as required and measure survey and drawing or information acquisition work, practice thrift the cost, the measurement of carrying out regions such as shallow water territory and reef district that can be more convenient to other equipment of load that can be convenient go on when carrying out the multitask.

Yan Xinping

Papers

Multi-objective path planning for unmanned surface vehicle with currents effects.

Self-adaptive adjustable device arranged on maritime cruising search and rescue unmanned ship

New insights into airfoil sail selection for sail-assisted vessel with computational fluid dynamics simulation:

Self-adapting sail capable of generating power

A unmanned surveying vessel for underwater topography survey and drawing